1. Field of Invention
The present invention relates to a projector.
2. Description of Related Art
Hitherto, it has been known that a projector is used during the presentation at conferences, academic meetings, exhibitions, or the like. In such a projector, the light flux emitted from a light source device is modulated by an optical modulator according to image information, to form an optical image, and the optical image is projected in an enlarged manner by a projection optical system.
In such a projector, high brightness of a light source is required in order to sharply display the projected optical image, and the heat generated by the light source must be radiated outside.
Thus, an exhaust structure to exhaust the air heated inside the projector outside by a fan is employed (see Japanese Unexamined Patent Application Publication No. 11-354963, for example).
In the exhaust structure, a centrifugal fan is employed as a fan to exhaust the air inside the projector outside.
An inlet of the exhaust sirocco fan is disposed along an optical path plane formed of a light source lamp as a light source device, a liquid crystal panel as an optical modulator, and a projection lens as a projection optical system.
The exhaust sirocco fan sucks the air heated by the liquid crystal panel, the light source lamp, or the like located above the inlet, and exhausts the air in the projecting direction of the light flux from the projection lens, i.e., from the front side of the projector to the outside.
However, in the above exhaust structure, the exhaust sirocco fan is located below the liquid crystal panel and the light source lamp or the like so that the inlet of the exhaust fan is disposed along the optical path plane. Thus, the number of revolutions of the exhaust fan must be increased to suck the air heated by the light source lamp and the liquid crystal panel or the like, i.e., the ascending air of smaller density downwardly.
Therefore, problems occur in that it is difficult to efficiently suck the air inside the projector by the exhaust sirocco fan, the noise level of the exhaust fan itself becomes high, and calmness of the projector cannot be ensured.
Accordingly, in light of the above problems, an object of the present invention is to provide a projector which can improve the exhaust efficiency by efficiently sucking the air inside the projector, and ensure calmness.